INLAYS & ONLAYS
To repair damage to the tooth’s biting surface, rather than using a
simple filling, or a crown, a dentist will often use an inlay, or an
onlay. Inlays and Onlays can be made from porcelain, gold, or
composite or ceramic resin, although porcelain is now becoming the
material of choice because of its strength and potential to match the
natural color of your tooth.
An inlay is similar to a filling and lies inside the cusp tips of the
tooth. They are custom-made to fit the prepared cavity and are then
cemented into place. An onlay is a more extensive reconstruction that
covers one or more cusps of a tooth. Onlays are indicated in
situations where a substantial reconstruction is required. However,
more of the tooth structure can be conserved compared to the placement
of a crown.
Inlays and Onlays are applied in two dental visits. At the first
visit, the old filling, or decay, is removed, and the tooth is
prepared for the inlay / onlay. The dentist will then make an
impression of the tooth, and send this impression to a dental
laboratory. This impression will be used by the laboratory to
construct a custom-made porcelain, or gold inlay / onlay. At this
time the dentist will place a temporary sealant on your tooth and
schedule a second appointment.
At the second visit, the temporary sealant is removed. Your dentist
will then ensure that the inlay / onlay fits properly in the tooth and
does not interfere with your bite. The inlay / onlay is then bonded
into the tooth with a strong bonding resin, and polished smooth.
An inlay or onlay is a solid filling made outside
the mouth, and then cemented into the tooth.
It is long lasting and made of porcelain bonded
to metal, or of pure porcelain.
This is a superior type of restoration that is
used to replace unsightly, discolored fillings.
The dentist removes the unattractive filling, and
takes an impression, which is sent to the dental technician.
A natural looking replacement filling is then
A temporary filling will be placed in the tooth
to protect it while the restoration is being made.
The filling is then placed into the prepared
cavity and held in place by cement.
Advantages & Disadvantages of Inlays & Onlays
- More costly than amalgam or composite
- Can fracture
Takes two appointments
- Highly esthetic
- No metal shows
- Strong once bonded to tooth
- Well-sealed tooth
- Will not stain
- Will insulate the tooth
- Well suited for large cavities
- Long lasting
Long time evaluations of ten years time showed a very good
durability of porcelain restorations which is similar to those of gold
restorations. In general, ceramic Inlays or Onlays can replace old and
damaged fillings or new carious lesions. However there has to be a
certain amount of tooth substance left after removal of the old
restoration or caries to provide enough stability for the ceramic
restoration. This is the reason why a decision on the indication for a
ceramic restoration should be individually made by the dentist for
each situation. This will ensure a long durability of the restoration.